English
Related papers

Related papers: Adaptive variational algorithms for quantum Gibbs …

200 papers

While recent advances have established efficient quantum algorithms for preparing Gibbs states of finite-dimensional systems, comparable complexity results for bosonic and other infinite-dimensional models remain unexplored. We introduce…

Quantum Physics · Physics 2026-04-08 Simon Becker , Cambyse Rouzé , Robert Salzmann

Efficient simulation of a quantum system generally relies on structural properties of the quantum state. Motivated by the recent results by Bakshi et al. on the sudden death of entanglement in high-temperature Gibbs states of quantum spin…

Quantum Physics · Physics 2026-01-21 Akshar Ramkumar , Yiyi Cai , Yu Tong , Jiaqing Jiang

Calculating the properties of Gibbs states is an important task in Quantum Chemistry and Quantum Machine Learning. Previous work has proposed a quantum algorithm which predicts Gibbs state expectation values for $M$ observables from only…

Quantum Physics · Physics 2024-09-10 Arnav Sharma , Kevin Obenland

The preparation of quantum states using short quantum circuits is one of the most promising near-term applications of small quantum computers, especially if the circuit is short enough and the fidelity of gates high enough that it can be…

Quantum Physics · Physics 2015-10-07 D. Wecker , M. B. Hastings , M. Troyer

We provide an efficient and general route for preparing non-trivial quantum states that are not adiabatically connected to unentangled product states. Our approach is a hybrid quantum-classical variational protocol that incorporates a…

Strongly Correlated Electrons · Physics 2019-03-08 Wen Wei Ho , Timothy H. Hsieh

Estimating thermal expectation values of observables is a fundamental task in quantum physics, quantum chemistry, and materials science. While recent quantum algorithms have enabled efficient quantum preparation of thermal states,…

Quantum Physics · Physics 2026-02-16 Jiaqing Jiang , Jiaqi Leng , Lin Lin

Quantum computers are a highly promising tool for efficiently simulating quantum many-body systems. The preparation of their eigenstates is of particular interest and can be addressed, e.g., by quantum phase estimation algorithms. The…

Quantum Physics · Physics 2025-08-28 Xiaoyu Liu , Benjamin F. Schiffer , Jordi Tura

We propose incorporating multi-qubit nonunitary operations in Variational Quantum Thermalizers (VQTs). VQTs are hybrid quantum-classical algorithms that generate the thermal (Gibbs) state of a given Hamiltonian, with applications in quantum…

Quantum Physics · Physics 2025-03-28 Elias Zapusek , Kristina Kirova , Walter Hahn , Michael Marthaler , Florentin Reiter

Emerging quantum hardware provides new possibilities for quantum simulation. While much of the research has focused on simulating closed quantum systems, the real-world quantum systems are mostly open. Therefore, it is essential to develop…

Quantum Physics · Physics 2024-02-14 Huo Chen , Niladri Gomes , Siyuan Niu , Wibe Albert de Jong

We propose new quantum algorithms for thermal and ground state preparation based on system-bath interactions. These algorithms require only forward evolution under a system-bath Hamiltonian in which the bath is a single reusable ancilla…

Quantum Physics · Physics 2025-12-19 Zhiyan Ding , Yongtao Zhan , John Preskill , Lin Lin

We propose a method based on deep reinforcement learning that efficiently prepares a quantum many-body pure state in thermal or prethermal equilibrium. The main physical intuition underlying the method is that the information on the…

Quantum Physics · Physics 2023-01-30 Shotaro Z. Baba , Nobuyuki Yoshioka , Yuto Ashida , Takahiro Sagawa

Gibbs state preparation is an important subroutine in quantum computing. In this work we use the detectability lemma to improve Gibbs state preparation. Specifically, we design new Gibbs state preparation methods that do not rely on…

Quantum Physics · Physics 2026-04-09 Di Fang , Jianfeng Lu , Yu Tong , Chu Zhao

Preparing the ground states of a many-body system is essential for evaluating physical quantities and determining the properties of materials. This work provides a quantum ground state preparation scheme with shallow variational warm-start…

Quantum Physics · Physics 2023-03-21 Youle Wang , Chenghong Zhu , Mingrui Jing , Xin Wang

A quantum system coupled to a bath at some fixed, finite temperature converges to its Gibbs state. This thermalization process defines a natural, physically-motivated model of quantum computation. However, whether quantum computational…

Quantum Physics · Physics 2025-01-15 Thiago Bergamaschi , Chi-Fang Chen , Yunchao Liu

A promising avenue for the preparation of Gibbs states on a quantum computer is to simulate the physical thermalization process. The Davies generator describes the dynamics of an open quantum system that is in contact with a heat bath.…

Quantum Physics · Physics 2023-10-11 Patrick Rall , Chunhao Wang , Pawel Wocjan

Quantum state preparation is an important class of quantum algorithms that is employed as a black-box subroutine in many algorithms, or used by itself to generate arbitrary probability distributions. We present a novel state preparation…

Quantum Physics · Physics 2020-06-02 Yutaro Iiyama

Sampling from Gibbs states -- states corresponding to system in thermal equilibrium -- has recently been shown to be a task for which quantum computers are expected to achieve super-polynomial speed-up compared to classical computers,…

Quantum Physics · Physics 2026-01-28 Joel Rajakumar , James D. Watson

We provide explicit circuits implementing the Kitaev-Webb algorithm for the preparation of multi-dimensional Gaussian states on quantum computers. While asymptotically efficient due to its polynomial scaling, we find that the circuits…

Quantum Physics · Physics 2021-09-24 Christian W. Bauer , Plato Deliyannis , Marat Freytsis , Benjamin Nachman

Preparing the ground state of a system is an important task in physics. We propose a quantum algorithm for preparing the ground state of a physical system that can be simulated on a quantum computer. The system is coupled to an ancillary…

Quantum Physics · Physics 2018-05-14 Hefeng Wang

Preparing thermal equilibrium states is an essential task for finite-temperature quantum simulations. In statistical mechanics, microstates in thermal equilibrium can be obtained from statistical ensembles. To date, numerous ensembles have…

Quantum Physics · Physics 2025-05-23 Yasushi Yoneta